<template>
  <div class="header">
    <!-- 折叠按钮 -->
    <div class="collapse-btn" @click="collapseChage">
      <i class="el-icon-menu"></i>
    </div>
    <div class="logo">后台管理系统</div>
    <div class="header-right">
      <div class="header-user-con">
        <!-- 全屏显示 -->
        <div class="btn-fullscreen" @click="handleFullScreen">
          <el-tooltip effect="dark" :content="fullscreen?`取消全屏`:`全屏`" placement="bottom">
            <i class="el-icon-rank"></i>
          </el-tooltip>
        </div>
        <!-- 用户头像 -->
        <div class="user-avator"><img src="../../assets/img/img.jpg"></div>
        <!-- 用户名下拉菜单 -->
        <el-dropdown class="user-name" trigger="click" @command="handleCommand">
                    <span class="el-dropdown-link">
                        {{username}} <i class="el-icon-caret-bottom"></i>
                    </span>
          <el-dropdown-menu slot="dropdown">
            <a href="http://blog.gdfengshuo.com/about/" target="_blank">
              <el-dropdown-item>关于作者</el-dropdown-item>
            </a>
            <a href="https://github.com/lin-xin/vue-manage-system" target="_blank">
              <el-dropdown-item>项目仓库</el-dropdown-item>
            </a>
            <el-dropdown-item divided command="loginout">退出登录</el-dropdown-item>
          </el-dropdown-menu>
        </el-dropdown>
      </div>
    </div>
  </div>
</template>
<script>
import bus from '../common/bus'

export default {
  data () {
    return {
      collapse: false,
      fullscreen: false,
      name: '小泽',
      message: 2
    }
  },
  computed: {
    username () {
      let username = JSON.parse(sessionStorage.getItem('user')).userName
      return username ? username : this.name//eslint-disable-line
    }
  },
  methods: {
    // 用户名下拉菜单选择事件
    handleCommand (command) {
      if (command == 'loginout') {//eslint-disable-line
        localStorage.removeItem('ms_username')
        this.$router.push('/login')
      }
    },
    // 侧边栏折叠
    collapseChage () {
      this.collapse = !this.collapse
      bus.$emit('collapse', this.collapse)
    },
    // 全屏事件
    handleFullScreen () {
      let element = document.documentElement
      if (this.fullscreen) {
        if (document.exitFullscreen) {
          document.exitFullscreen()
        } else if (document.webkitCancelFullScreen) {
          document.webkitCancelFullScreen()
        } else if (document.mozCancelFullScreen) {
          document.mozCancelFullScreen()
        } else if (document.msExitFullscreen) {
          document.msExitFullscreen()
        }
      } else {
        if (element.requestFullscreen) {
          element.requestFullscreen()
        } else if (element.webkitRequestFullScreen) {
          element.webkitRequestFullScreen()
        } else if (element.mozRequestFullScreen) {
          element.mozRequestFullScreen()
        } else if (element.msRequestFullscreen) {
          // IE11
          element.msRequestFullscreen()
        }
      }
      this.fullscreen = !this.fullscreen
    }
  },
  mounted () {
    if (document.body.clientWidth < 1500) {
      this.collapseChage()
    }
  }
}
</script>
<style scoped>
  .header{
    position:relative;
    box-sizing:border-box;
    width:100%;
    height:70px;
    font-size:22px;
    color:#fff;
  }
  .collapse-btn{
    float:left;
    padding:0 21px;
    cursor:pointer;
    line-height:70px;
  }
  .header .logo{
    float:left;
    width:250px;
    line-height:70px;
  }
  .header-right{
    float:right;
    padding-right:50px;
  }
  .header-user-con{
    display:flex;
    height:70px;
    align-items:center;
  }
  .btn-fullscreen{
    transform:rotate(45deg);
    margin-right:5px;
    font-size:24px;
  }
  .user-name{
    margin-left:10px;
  }
  .user-avator{
    margin-left:20px;
  }
  .user-avator img{
    display:block;
    width:40px;
    height:40px;
    border-radius:50%;
  }
  .el-dropdown-link{
    color:#fff;
    cursor:pointer;
  }

</style>
